2009 Volvo S60 Owner's Manual - Page 230

10 Audio Audio systems - specifications HU-650 10 NOTE 4×25 W 4 Ohm 12 V, negative ground 4×50 W or 4×75 W Output Impedance Voltage required External amplifier Alarm! is displayed when an alarm message is sent. The function is used to warn the driver of a serious accident or disaster situation. NOTE The optional supplementary amplifier (HU-850) may be mounted under the front passenger's seat. If the floor of the vehicle has become soaked for any reason, do not turn on the radio. This would cause damage to the amplifier. Contact a trained and qualified Volvo service technician. Radio frequency range: AM FM HU-850 Output Impedance Voltage required External amplifierA Radio frequency range AM FM A 530 - 1710 kHz 87.7 - 107.9 MHz 1×25 W center speaker 4 Ohm 12 V, negative ground 4×50 W or 4×75 W Low battery voltage If the level of battery voltage is low, a message will be displayed. The vehicle's energy conservation function may switch off the audio system. Recharge the battery by starting the engine. 530 - 1710 kHz 87.7 - 107.9 MHz The HU-850 must be connected to an external amplifier. 230